The overall goal of this contract is to determine the chromosomal location of mutant genes that predispose to cancer in families being studied by investigators from CEB, and EEB, NCI. The cancers or cancer-causing conditions are those that appear to have a genetic causation--that is, they segregate within family members in a pattern characteristic of an autosomal dominant trait. The first step towards this goal is for the laboratory to assay blood and serum specimens submitted to them from NCI from both affected and unaffected members of all living generations of the studied families for polymorphisms of red blood cell antigens and enzymes and serum proteins of known chromosomal location. When the assay results are available for each family, Dr. S. Bale or another NCI investigator then analyses the pattern of distribution of the protein polymorphisms together with the pattern of disease transmission in the family to determine if the disease gene and any one of the polymorphisms co-segregate; a positive result would indicate that the disease gene is physically linked to the polymorphic locus.